The present invention relates to a communication method for an extending device in a communication system, and more particularly, to a communication method capable of dynamically adjusting the frequency bands of transmitting traffic flows.
A wireless distribution system (WDS), a system that enables the wireless interconnections among access points in a network, allows a wireless network to be expanded via using multiple access points (APs), such as range extenders and mesh APs, without using a wired backbone to link the multiple APs. The advantage of WDS over other solutions is that the WDS preserves media access control (MAC) addresses of client frames across the links between the APs.
For example, please refer to FIG. 1, which is a schematic diagram of a conventional WDS 10. As shown in FIG. 1, the WDS 10 comprises an AP, a range extender RE, a plurality of stations STA1 and a plurality of stations STA2. The AP connects to a backhaul network and communicates with the range extender RE via links LRAA in a frequency band FB_A and links LRAB in a frequency band FB_B. The range extender RE is a dual-band range extender comprising network interface cards NIC1 and NIC2. The range extender RE connects to the plurality of stations STA1 via links LSRA in the frequency band FB_A and connects to the plurality of stations STA2 via links LSRB in the frequency band FB_B. Conventionally, the range extender RE is limited to relay traffic flows between the stations STA1 and the AP via the links LRAA and LSRA, and to relay traffic flows between the stations STA2 and the AP via the links LRAB and LSRB. That is, the range extender RE only can relay the traffic flows in the same frequency band.
Please refer to FIG. 2, which is a schematic diagram of a conventional WDS 20. The WDS 20 is similar to the WDS 10, thus the components and the signals with the similar functions are denoted by the same symbols. Different from the WDS 10 shown in FIG. 1, the WDS 20 only comprises the stations STAT that are connected to the range extender RE in the frequency band FB_A. Since the range extender RE is limited to relay the traffic flows in the same frequency band, the traffic loads of the frequency bands FB_A and FB_B are unbalanced and the frequency band FB_B is completely wasted in the example of FIG. 2. Thus, how to optimize the performance of the WDS becomes a topic to be discussed.